The production of activated carbons and their employment in problems linked with the environmental protection and reparation have been notably increased in the last two decades. In this work the possibility activated carbons preparation from shells of the Honduran mahogany fruit and mammee seeds was examined by “chemical” activation with phosphoric acid. The influence of the temperatures (from 300 to 500°C), the activation time (from 60 to 120 minutes) and the acid concentration (from 30 to 50% (w/w) on the characteristics of the obtained product was analyzed. It was determined that the resources studied and the activating agent used were appropriate to prepare activated carbons whose quality was affected by the preparation conditions.